One common feature of unscientific belief systems is that they do not change in the face of new evidence. They tend to evolve like cultural beliefs or marketing campaigns, but do not appear to be affected by scientific evidence in any meaningful way.

One great example of this is the idea the autism is linked to vaccines (to be clear up front, it isn’t) This idea had a few important factors in its origin. The first was simply the existing anti-vaccine movement searching for anything to blame on vaccines. The second, and perhaps decisive, factor was the now discredited and withdrawn study by Andrew Wakefield linking autism to the MMR vaccine.

Even as the MMR claim was dying, the anti-vaccine community was moving onto the next target – mercury (specifically the preservative Thimerosal). This was the target of the book Evidence of Harm by David Kirby. This also created common cause between the anti-vaccine movement, and separate “mercury militia” blaming many modern ills on mercury, and some environmentalists (most prominently Robert Kennedy Jr.) who are keen to blame medical problems on any environmental exposure, including mercury and/or vaccines.

There are several lines of evidence that bear on the question of whether or not mercury or any vaccine exposure contributes to the incidence of autism. We can simply ask observationally is there any correlation between any type of vaccine exposure and the risk of developing autism. After years of study the short answer is no – there is no demonstrable link between vaccines and autism.

Because mercury and thimerosal as a vaccine ingredient is often blamed, we can say separately that there is no correlation between exposure to thimerosal and autism. In fact, thimerosal was removed from the routine vaccine schedule in the US around 2002. At the time antivaxxers (including David Kirby) predicted that autism rates would plummet – they didn’t. They have continued to rise at the exact same rate without a blip. (This is likely to change eventually as the diagnosed rate reaches the true rate, and also because of changing diagnostic criteria.)

We can also explore the causes of autism. If we find that autism, for example, is primarily a genetic disorder, then there may not be a significant role for environmental factors. In fact the research has been showing that autism is a dominantly genetic group of disorders (likely not one discrete entity). The anti-vaccine community mostly ignores this evidence, or dismisses it with a wave of the hand but without mounting even a single coherent argument that I have ever heard.

Part of what leads some parents to believe that vaccines caused their children’s autism is that the clinical signs of autism become apparent after children have received many of their vaccines. The childhood vaccine schedule includes many shots between birth and 18 months. While age of diagnosis can vary, many parents notice the signs of autism between 1 and 3 years of age and so there is likely to be some apparent temporal association by chance alone.

This raises another important question in the vaccine – autism controversy – at what age does autism truly begin? Careful scientific studies have found clinical signs of autism as early as 6 months of age. This is before the first MMR dose is typically given, which is at 12 months. If the earliest observable signs of autism are present at 6 months it is very likely that the processes changing brain structure and function begin before six months. The true onset of autism is therefore before all but the earliest vaccine doses.

This makes it much more difficult to blame autism on vaccines. This, of course, doesn’t stop from doing so.

A new study sheds further light on this question and likely pushes back the onset of autism into the womb. The researchers examined the brains of children with autism and typical children who happened to die. They found that the brains of most of the autistic children contained patches of disorganized neurons (especially in layers 4 and 5 and the prefontal cortex, for those interested). The organization of neurons occurs primarily in the third trimester. The most plausible explanation for these findings is that they are resulting from a process that affects brain organization at this developmental stage – in the womb.

Of course, this is just one exploratory study. Like all new findings in science, they need to be replicated. The results are fairly objective and robust, however.

Assuming the results pan out, this would provide further evidence that autism is likely to be a genetic disorder affecting early brain development. Onset in the womb, of course, would eliminate childhood vaccines as a cause.

We already know, however, that this won’t stop the anti-vaccine community from continuing to claim that vaccines or mercury cause autism. The evidence is not relevant to their beliefs. They already have shifted to blaming the mother’s vaccines.

Conclusion

Multiple independent lines of evidence strongly suggest that autism is a dominantly genetic disorder affecting early pre-natal brain development. Further, there is no link between vaccines or mercury and the risk of developing autism. This new study is just one tiny piece of the overall puzzle, but it is consistent with the big picture.

I have yet to hear of any prominent anti-vaccine activist, however, alter their rhetoric about vaccines in response to scientific evidence. Perhaps there is an exception out there I have not heard of, but it would be just that – an exception. For the most part the anti-vaccine movement has not budged from their position, despite the scientific evidence.

Like other science-denial and anti-science movements, they have their studies to cherry pick, their fringe researchers to idolize (like Andrew Wakefield and the Geiers), and their conspiracy theories to dismiss all inconvenient evidence.

21 Responses to “When Does Autism Begin?”

“They already have shifted to blaming the mother’s vaccines.”
Among some of the internet comments I’ve seen on this study so far, some anti-vax advocates are sticking with blaming the childhood vaccines and shifting the goal posts the other way, insisting that the “toxic load of pollutants” causes neurological dysfunction of some sort, even if it isn’t autism. So they want to change the child’s diagnosis instead of acknowledging that the cause lies elsewhere.

Most anti-vax parents I think are motivated by wanting to feel like they are in control of their children’s health, and they can control whether or not they receive vaccines. The prostpect of autism being a genetic issue is scary because there’s not really anything that can be done about a child inheriting a trait.

So there will be a variety of logical acrobatics out there to land on the “vaccine = bad” conclusion, no matter what evidence is found.

But are they in fact “science-denialists” and an “anti-science movement” as you’re claiming in your article? They are definitely an *anti-vaccination* group and their belief system appears to be, on what evidence we have, irrational. But are members of this group against science in general? Are they also creationists? Do they believe the moon landings were staged? Do the majority argue that JFK was assassinated by an organised group?

The observation I’m making here is that advocacy groups stereotypically have the need to create an inner circle and then certain external groups that are labelled as ‘enemies of the state’ so to speak. I suppose ‘science denialist’ is as good a label as any, given your subject matter, and the fact that science enjoys enormous prestige in our societies. So what could be more evil than to demarcate a particular group as *against science itself* ?

But is it really that simple? There is nothing particularly wrong with the article that you wrote, except for your closing remarks, because the world and the people in it, are considerably more nuanced here, than your portrait of good versus evil. (Although unfortunately the potential for harm from this group is real.)

Wouldn’t it be better to identify this group for what they are – misinformed and emotionally invested traumatized parents – rather than sweep them into a wider (and frankly imaginary), idealogical battle as your enemy combatants?

*Feel free to block me from your blog for posting this if you’re unable to respond or don’t wish to.

Seriously, if you are unable to comprehend and parse simple English I would avoid making yourself look even more stupid by posting anymore.

An anti-science movement is a movement who at it’s core is anti-science in it’s belief. If that is their lack of understanding of vaccine science or gravity science or AIDS science, they are denying science in one form or another.

They use conspiracy theories to cover for the lack of science that their beliefs have.

If anything your interpretation of those comments was more revealing about how you think and if I were you I would consider thinking about your motives for posting here because there certainly seems to be nothing positive or constructive in any your narratives even when you seem to be agreeing with the theme of the blog post.

You would think with amount of the @*&$ Will throws against the wall, that something would stick, but I struggle to find any useful contributions.

Will- antivaccinationists are science denialists because they are denying the science relevant to vaccinations. Your misunderstanding seems to stem from your thinking of science as a collection of subjects, rather than a rigorous process of testing hypotheses. Either that, or you are so ideological driven to be a Steven Novella contrarian, that it overrides any desire to ensure basic reading comprehension when reading his posts.

I’m hoping you’ll respond to my above post but given that you raise certain interesting philosophical questions in some of your posts, there is little point in me continuing to go around in circles if your reaction is to name call and engage in other regrettable juvenile responses.

Anyway, these were some of the questions I posed that were avoided or ignored -

With regards to your post on ‘standards’ who decides who manages those standards? What are your views on the relationship to ‘standards’ with that of public discourse?

What do you mean by consensus? Do you have a precise definition or it is more of an idealogical motto? How do you determine what the consensus is? If this something you work out yourself? Do you get it from Wikipedia? Do you ask your friends? Is it something that smart people ‘just know’ ?

Assuming you have some means of determining what a consensus is (an ability you claim to possess), what does it include or exclude and exactly what is its epistemological status? Is it based on a survey of expert opinion? Or is it a proxy for evidence? If so, why not refer to the evidence instead? Since a consensus can exist among astrologers, physicists, ecologists, anthropologists, economists, psychoanalysts, and so forth, does the reliability of a consensus vary? If so, who decides which ones are sound and which ones are not?

With reference to the creation of hate groups (a constant theme in most of your posts) what is the criteria for membership of one of your hate groups? For example, with regard to ‘science deniers’ who decides who qualifies for membership to such groups? Since virtually all these groups profess confidence in science in general, but have certain objections to certain scientific claims (be that evolutionary theory or vaccination) the labelling you use does not appear to be particularly precise. Is that vagueness intentional? Who is worse? An Andrew Wakefield who works (or worked) within the scientific mainstream but who causes significant damage through faulty, bad or bogus research, or a Young Earth Creationist who few but his immediate circle take particularly seriously? Does Andrew Wakefield qualify as a science denier? Are bad researchers science deniers? If so, what hate group label are they given?

I have a bunch of other questions that were never answered, but I’ll put them aside as this post would get too long. So I’ll end this with a few closing remarks. I am curious about advocacy groups and occasionally visit them on their own turf. I usually try to a be a little provocative or cut straight to some pertinent questions to gauge the maturity of the person of interest. You sort of failed that test on every possible level. However, in your defence, for all I know, you do get a lot of postings from members of your hate groups who dislike you, so perhaps that is now your entrenched reaction to any form of criticism. My point is that everybody these days declares they are on the side of rationality, enlightenment ideals, the scientific method, and so on. But it’s one thing to profess these virtues, another to demonstrate them. I understand a lot of your posts are about ghosts and goblins, bigfoot and all that. As such you’re not going to appeal to mainstream public intellectuals, because, well, it’s kind of dumb stuff isn’t it? The sorts of interests kids grow out of. But, that’s fine. One could argue that playing golf is kind of a goofy activity, so each to his own! Anyway, I mention this because if you’re going to attract a certain class of readership… Given that situation, I think you should always try to present yourself in the best light. Don’t name call. Don’t be quick with labels. Forget the psycho babble talk pretending to read the mind of your critic. It’s dumb stuff and it means your readership are encouraged to exercise their worst behaviours. That’s not consistent with the enlightenment virtues you claim to profess.

Perhaps it is not a good idea to engage your criticism before Steve does, lest I be called a ‘henchman’ a second time (and that from a person that complains as much about ‘labeling’ as you do). However, having read several of your latest comments, I do have one or two (in fact, exactly two) observations to make.

First, every time you utter some criticism of this blog, you invariably end it with a ‘feel free to ban me’ clause, even though, by now, you must be aware that you do not get banned for dissenting opinions here. Or do you? Were there ever any posts of yours that have been banned? If so, I support your right to free speech. But if not, then your constant mention of ‘banning’ is nothing other than an unfair rhetorical device. Of course, if you tried to quote some scientific evidence in blogs of these anti-science groups you mention you frequent in order to satiate your curiosity, then the experience of being banned is hardly, if at all, likely to be unfamiliar to you.

Second, there is a short answer to your last paragraph (and many of your earlier questions) and, strangely enough, this answer can be expressed by a Biblical quote: ‘By their deeds ye shall know them’.

The point being, it is not the ‘scientific sceptics’, or anyone else for that matter, who ‘decides’ who is an anti-science activist. Anti-science position (like any other philosophical position) is defined by the substance of the claims made, by mode of reasoning applied to their support, and, above all, by the general attitude toward evidence and fact verification. It is there that the true importance of intellectual standards and criteria of quality in assessing evidence lies. This has nothing to do with a consensus, or lack thereof. Or, to paraphrase the spirit of the Enlightenment: the rules of Reason are written by Reason itself. Emphatically not by any of us. Neither by few nor by many.

Therefore your repeated attempts to frame the discussion of the above mentioned rules, standards and criteria in terms of ‘who gets to decide’ are about equally as meaningful as if you claimed that Pythagoras ‘decided’ what the square of the hypothenuse should be equal to. Perhaps, in today’s democratic times, we should reject Pythagoras’ famous authoritarianism (‘Autos ephe’ and all that) and simply cast a vote? Or how about a referendum to finally overthrow the whole of oppressive Euclidian geometry? After all, Lobachevsky’s idea that parallel lines do eventually cross somewhere sounds much more hopeful – perhaps we too may eventually find some point(s) of agreement some day.

Sorry Aardwak, I rarely read comments except Steven’s so this is the first time I’ve read yours. It’s Steven’s blog so he is free to ban me if he so wishes. I don’t think it’s a free speech issue. At some point he may do that or if he continues to eschew my philosophical questions, I’ll go away and annoy some other advocacy group. It seems odd that he wants to take various philosophical positions – even the name of his blog has a philosophical pretence – but doesn’t wish to defend himself. The reasoning I think is that he truly believes he’s picked the ‘true’ or ‘correct’ positions so he doesn’t need to defend them. Anyone who questions his judgement is a denier, or a troll or something else. Also perhaps he’s never had any actual formal education in philosophy so doesn’t feel confident that he could defend himself on first principles, so to speak, confidently. (This is all speculation, BTW.) Still, it doesn’t hurt to ask the questions and if he offended by them, that to me means he is taking all this a little *too* seriously. The ‘feel free to ban me’ comment I’ve added lately is just a little bit of fun I’m poking at his bad temper, since his ‘threat’ to bad me. FYI, Steven hadn’t banned or blocked any of my posts, yet.

Unfortunately I don’t follow the point of your second observation. Euclidian geometry has rules, in its particular case called axioms. From these you draw conclusions using formal procedures, which must always be correct, within the limits of the system. We don’t have to get high brow here. Poker has rules. A flush beats a straight. You don’t vote on it. You don’t seek consensus. You refer back to the rules. The rules can be complex, so it might not be simple to work out if a claim is true, but if the claim is covered by the system, it’s not a matter of debate. But scientific research is not like that. We think we know some of the rules, but know we don’t know some of them. Often there are rules we don’t know we don’t know. So people invent other methods for trying to decide if something is true. They can vote on it. Or try to calculate the majority of educated guesses. All these things might sound good if not questioned, but they aren’t taken seriously in the scientific literature that studies the history and philosophy of science. It’s always useful to ask. Did these technique work in the past? If the answer is no, it’s pretty likely they aren’t going to work in the future either.

I’m pretty sure Steven Novella has this kangaroo on ignore.
I suggest we follow his lead.
He adds absolutely nothing to the discussion.
And I sure as Hell don’t want to see him get what he’s been after for some time now – getting banned.
He will wear that as a badge of honour.

“It’s Steven’s blog so he is free to ban me if he so wishes. I don’t think it’s a free speech issue. At some point he may do that or if he continues to eschew my philosophical questions, I’ll go away and annoy some other advocacy group.”

If you needed any more evidence that Will is nothing more than a troll, here it is.

The thing is, Will, I and others have answered your questions. Ad nauseum. You either don’t read, don’t comprehend, or simply wish to ignore the answers. You have made your agenda clear. Your own description of your behavior is that of a troll. You criticize name calling, but you are the one who is name calling and labeling.

What makes a group anti-science? When they engage in anti-scientific arguments and behavior. Evidence does show that when a person is motivated to deny the science of one claim because of ideology, they do tend to deny science itself. They become anti-science to maintain their ideology.

Consensus is not that difficult a concept. If the vast majority of experts in a field agree on a specific position, we can deem that position a consensus. For most things you simply have to be familiar with the literature and what the experts are saying. You can even talk directly to them. For some issues panels of experts are assembled to systematically review all evidence and arguments and come up with a formal consensus. I can know what that consensus is because I can read. It doesn’t take any special powers.

Who sets standards? Each group sets their own standards. Wikipedia can decide on their own standards. So do journals, universities, news outlets, and professions. They each have their own process for doing so. This is so obvious is does make me question why you felt the need to ask it.

I don’t hate or engage in hate groups. I engage in science-based and rational analysis and criticism of psuedoscience in the public square. I am completely transparent about my process. I often discuss the process itself.

Strange I didn’t see any of them yet I read each post where I’ve commented and monitor all your comments. Perhaps you are being… what’s the correct word here… not entirely liberal with the facts?

“You criticize name calling, but you are the one who is name calling and labeling.”

Interesting, could you provide examples?

“What makes a group anti-science? When they engage in anti-scientific arguments and behavior. Evidence does show that when a person is motivated to deny the science of one claim because of ideology, they do tend to deny science itself.”

Could you site the evidence? I can think of a few horrible studies that have been debunked. I hope you won’t cite those…

“Consensus is not that difficult a concept. If the vast majority of experts in a field agree on a specific position, we can deem that position a consensus.”

What is the basis of the agreement? You seem to skim past my questions and answer a different one each time.

“For most things you simply have to be familiar with the literature and what the experts are saying.”

So you’re saying you do a lot of reading and sort of wing it? I think I missed something. How do you arbitrate on complex scientific debates if you have no knowledge of the field? Is it a vote count thing?

“You can even talk directly to them. For some issues panels of experts are assembled to systematically review all evidence and arguments and come up with a formal consensus.”

I appreciate the NAS and other bodies frequently institute committees to do literature reviews but certain reviews are better than others, and some reviews are, frankly, terrible for various reasons. (Such as being rather unambitious in terms of the issues they attempt to address.) And how does one decide if there isn’t a review to cite? You’re being terribly vague here.

“Who sets standards? Each group sets their own standards. Wikipedia can decide on their own standards. So do journals, universities, news outlets, and professions. They each have their own process for doing so. This is so obvious is does make me question why you felt the need to ask it.”

So you’re equating whatever mysterious process Wikipedia institutes with what a journal or university does. They have the same professional standards? This is an interesting claim. How do you know this? It sounds like a nonsense statement to me, but I’m assuming you can demonstrate this assertion to be true?

“I don’t hate or engage in hate groups. I engage in science-based and rational analysis and criticism of psuedoscience in the public square. I am completely transparent about my process. I often discuss the process itself.”

I never wrote that you hate. You don’t need to be a hater to lay the foundations for hate groups. Criticism of pseudo science is a fine ideal. How you go about addressing such problems is the issue. If your process is transparent, it would be great if you would describe it and perhaps address some of my more specific questions. But there is no hurry to do this. You’re busy, I’m busy.

Will – just above you accuse me of juvenile responses and then, coyly, of lying. Then you try to take the high ground by lecturing me about black and white, good vs evil, and how the world is more nuanced. Clearly you have not read and understood any significant amount of my writing.

Of course not all consensuses are equal. They are only as good as the body within which the consensus exists, and the process used to determine the consensus. A consensus could be robust and solid, or tenuous, even meaningless. I never exalted consensus as some magic or easy answer. It is very challenging – but that does not mean it’s impossible to determine that there is a robust consensus on a particular issue within a legitimate scientific profession.

And, as I have written explicitly before, a consensus could be wrong, but if you are a non-expert you would need to have a damn good reason for rejecting a stated consensus opinion of actual experts.

There is no way to remove judgement and fund of knowledge from this process. You see how you are creating silly straw men.

Which you then do again – I never equated the process of Wikipedia with that of a university. I said they each have their own standards and process. How is that equating them? We can judge them on their standards – are they reasonable and transparent, are they universally and fairly applied, etc. Again, judgement is required.

You want to understand my process? You don’t act like you do. You act as if you are desperate to create straw men based upon the worse possible interpretation of anything I write, to suit your stated agenda. But if you are really interested – seriously, just read my blog and make a sincere effort to understand what I am writing. You might also want to familiarize yourself with the intellectual virtue of being charitable. What you are doing is the opposite of that, which is informally called trolling.

I think this is where you miss the point in a big way. It is not the criticism of pseudo-science that is the ideal. The ideal is ensuring the science is understood and kept accountable. The exposing of pseudo-science is and other woo related issues is the by-product of this. You make many claims about what you think us as skeptics are all about, but you have yet to openly give a real opinion on any of the issues. You are the very definition of vacuous.

Forgive me for not following your suggestion immediately. I have no problem to let conversation end in ‘agreeing to disagree’, but only when I feel that each understands the other’s position clearly and that there are no additional relevant points not addressed. We are approaching the fulfillment of that criterion, as it appears, but still, another quick reply to Will seems to be in order.

@ Will,

Not that it matters too much, but we did have an exchange of opinion earlier in this blog, when the topic was whether neuroscience had a basis in reality. That is when you collectively called me, and several other commentators, ‘Dr. Novella’s faithful henchmen’ because we happened to generally agree that such a basis does exist. (Please do not think that I am offended, merely stating the facts.)

Actually, I think we may have found our ‘Lobachevskian point of intersection’ rather earlier that expected, for I agree with virtually all you said in your reply to me above. However, I fail to see how this supports the views you expressed above – or below. Specifically, I refer to your closing sentence:

‘Did these technique work in the past? If the answer is no, it’s pretty likely they aren’t going to work in the future either.’

Well, Will, scientific method has demonstrably worked in the past, as it quite obviously works in the present. Therefore, mutatis mutandis, it does seem pretty likely that it is going to work in the future as well.

For the benefit of those few who are still in the dark about Will’s trolling, since he claims to not read comments:

Steve stated:
“Who sets standards? Each group sets their own standards. Wikipedia can decide on their own standards. So do journals, universities, news outlets, and professions. They each have their own process for doing so.”

Will responds:
“So you’re equating whatever mysterious process Wikipedia institutes with what a journal or university does. They have the same professional standards? This is an interesting claim.”

Come on. Really? At this point, it is not just about not trying to understand Steve’s writing, you are actively trying to misunderstand.

Steve basically says that standards are set by each group, using their own processes, and you convert that into him saying that they all have the same standards. Somehow you took a straightforward explanation, and made it the complete opposite of what he wrote.

“Wikipedia can decide on their own standards. So do journals, universities, news outlets, and professions.”

And from that get:

“So you’re equating whatever mysterious process Wikipedia institutes with what a journal or university does. They have the same professional standards?”

“can decide on their own standards” does not, by any even wild stretch of interpretation that I can think of, equate to “They have the same professional standards.”

You brought up Poker, let’s use that analogy again. If I were to say that when the rules of Poker were being standardized, and when the rules of the card game of Bridge were being standardized, that each “standards committee” could decide on their own standards, would you respond by questioning whether each committee had the same standards? Or, because Poker and Bridge have different rules, would it be rather obvious that different standards might be used in the process of standardizing those rules?

So even aside from the fact that what Steve wrote did not in any way come anywhere close to even suggesting that “They have the same professional standards,” why would it enter your mind to think that he even might be saying that?

please Will, we’ve been begging you to stop since you appeared on that first thread.

Steve Novella says: ““Consensus is not that difficult a concept. If the vast majority of experts in a field agree on a specific position, we can deem that position a consensus.”

Will N responds with: “What is the basis of the agreement? You seem to skim past my questions and answer a different one each time.”

I’ll call you names, I have nothing to lose. In the above he answers your question directly and as usual you deny it. You’re one of two things, a troll or an idiot. I’m starting to think you’re a combination of the two…